Comparative analysis of radionuclide therapy with domestic and foreign radiopharmaceuticals based on Radium-223 chloride for the treatment of bone metastases

INTRODUCTION: Prostate cancer is called metastatic castration-resistant (mCRP) when it spreads to organs outside the prostate (for example, lymph nodes, bones, liver or lungs) and no longer responds to hormone therapy. Radium-223 is a radioactive molecule that emits strong radiation in a very small range around itself. It mainly gets into the bone, where the cancer has spread, and has a detrimental effect on cancer cells in this area.

OBJECTIVE: The purpose of the study was to prove the effectiveness, safety and identity of a domestic radiopharmaceutical drug based on Radium-223 chloride in comparison with the original drug. The main criterion for patient selection was diagnosis — metastatic castration-resistant prostate cancer with bone metastases in the absence of visceral metastases.

MATERIALS AND METHODS: The study involved 41 patients with an established oncological diagnosis who underwent planar bone scintigraphy in the «whole body” mode and PET/CT with ¹⁸F-PSMA. In all patients included in the study, the fact of metastatic lesions of the skeleton and the absence of visceral metastases were confirmed according to diagnostic studies before inclusion in the study. The effectiveness was assessed by comparing planar osteoscintigraphy and PET/CT data before treatment, after 4, 6 cycles and 3 months after the end of treatment, and pain syndrome was assessed. The safety of the drug was monitored by the results of the patient’s hematological profile over time before and after each cycle.

RESULTS: In the study group, out of the total number of patients at the start of the study, 8 patients (30.8%), according to instrumental studies, had disease progression in visceral metastases; 4 patients died (15.4%) (3 people from COVID-19 (11.5%), 1 due to progression of the main process (3.9%); in 15 patients (57.7%) stabilization of the process was noted skeletal system. In the control group, out of the total number of patients at the start of the study, 4 patients (26.7%), according to instrumental studies, showed progression of the disease through visceral metastases; 4 patients died (26.7%) (1 — due to progression of the main process (6.7%), 1 person from COVID-19, 1 patient due to heart failure, 1 — with a postmortem diagnosis of pulmonary embolism (20.0); in 8 patients (53.3%), stabilization of the process in the skeletal system was noted.

DISCUSSION: The results of the conducted studies have confirmed the high clinical efficacy and equivalent safety profile of the domestic radiopharmaceutical based on radium-223 chloride compared with the original one.

CONCLUSION: There were no statistically significant differences between the groups of patients, which allows us to conclude that the original and domestic radiopharmaceuticals based on Radium-223 chloride are completely consistent.

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